#include<stdio.h>
#include<math.h>
int main()
{
    int a,count = 0;
    for(a=5;a<=100;a+=5)
    {
        count ++;
        if(!(a%25))
        count++;
    }
    printf(" the number of 0 in the end of 100!is :%d\n",count);


    return 0;
}